1. Field of the Invention
This invention relates to an ink jet recording apparatus.
2. Related Background Art
An apparatus of this type has a discharge port of a minute diameter usually of the order of .phi.30-100 .mu.m for discharging recording liquid droplets.
Accordingly, if the apparatus of this type is left unused under room temperature or high temperatures for a long period of time, the water content in the recording liquid (ink) is vaporized and the viscosity of the ink near the discharge port is readily increased or the adherence of the ink occurs and thus, formation of recording liquid droplets becomes impossible in some cases.
So, some of apparatuses according to the prior art are provided with a cap for capping the discharge port during the non-operation of the apparatuses to thereby prevent the vaporization of ink from the discharge port, or are provided with a mechanism for forcibly sucking ink from the discharge port during the non-discharge of recording liquid droplets.
However, even in the conventional apparatuses provided as stated above, if the apparatuses are left unused under a high temperature environment for a long period of time or if use is made of special ink having high fixativenees and a low blotting rate, it has sometimes been the case that an increase in the viscosity of the ink in the discharge port portion or the adherence of the ink to the discharge port portion cannot be sufficiently coped with.